This disclosure relates in general to secure computing systems and, more specifically to high-assurance processing of packets of different classification levels amongst other things.
Governments classify information at different levels generally according to their sensitivity, for example, SECRET versus TOP SECRET. Users of the information are also classified by what level they are able to get access to. For example, someone with a SECRET clearance is not given access to TOP SECRET information. Procedures are put in place to avoid exposure to persons without the proper classification level.
In processing systems, physical security is used to prevent information of different classification levels from bleeding over to a different classification level. To process at multiple classification levels, there may be several devices running in parallel for each classification level. Devices that may be capable of running at multiple classification levels are run at one classification level, cleared out and then run at a different classification level. Intermixing of different classified information is generally taboo in these systems.
There are situations that require smaller cryptographic devices that can process different classification levels. Switching between classification levels takes time and slows down processing. Some have proposed trusted operating systems that can process information with more flexibility, but these solutions are avoided due to a lack of trust.